A dishwasher has a mean lifetime of [mu] years with an estimated standard deviation of [s] years. The lifetime of a dishwasher is normally distributed. Suppose you are a manufacturer and you take a sample of [n] dishwashers that you made.  Find the probability that the sample would have a mean lifetime less than [xbar] years?

Which of the following can be considered a probability distribution? Check all that apply. Hint: Recall that a probability distribution must contain probabilities (each P(x) must be between 0 and 1, inclusive). And, the sum of the probabilities must be 1.

A study where ill patients recorded their diets for a week, and the nutrients and calories were then recorded and analyzed. Is the study observational or experimental?    

Solve the problem.The stem-and-leaf plot below displays the ages of 30 attorneys at a small law firm.The youngest attorney is [a]and the oldest attorney is [b].

Determine the level of measurement for the variable below. High and low temperatures recorded for the northwest United States in the month of June.

Solve the problem.What is the relative frequency for Sophmores? Year inCollege Frequency Relative Frequency Freshman 600 Sophomore 560 ? Junior 440 Senior 400  

Which of the following is NOT a measure of variability?

El Presidente supermarket attempted to estimate the average amount all households in Tampa spend on groceries each week.  Households were separated by zip code, and 25 houses from each of the 56 zip codes were randomly selected. 1400 households were surveyed.

Select the best answer on the right to match the question on the left.

Solve the problem.What is the relative frequency for Juniors? Year inCollege Frequency Relative Frequency Freshman 600 Sophomore 540 Junior 460 ? Senior 400